Concrete wall forming system using fabric

ABSTRACT

A wall form assembly comprising a substantially rigid surface to maintain the form assembly in a predetermined orientation and at least one flexible fabric surface spaced from the rigid surface. The rigid surface and flexible fabric surface are interconnected by a plurality of flexible links to define a container with side walls to receive a flowable and settable wall forming material. The wall form assembly offers the advantages of being significantly lighter, less labour intensive and less expensive than existing formworks. The wall form assembly permits efficient waterproofing and insulation of the constructed wall.

FIELD OF THE INVENTION

[0001] This invention relates generally to the field of forms constructed to be filled with concrete or other flowable and settable materials, and more particularly to a pre-fabricated concrete wall forming system that includes at least one wall formed of fabric.

BACKGROUND OF THE INVENTION

[0002] Wall forms have been in existence since Roman times. While significant changes in materials have occurred over the years, the basic principle remains the same: create a cavity using spaced, rigid flat surfaces into which a flowable and settable building material is deposited and remove the surfaces after the material has set to leave the wall in place. in early times, the rigid surfaces were made from hand cut lumber. In more modern times, steel, plywood or even rigid plastic are used. Bracing to hold the forms together were made of rope or wood in the past. Now they are made from steel or plastic rods.

[0003] Current methods for forming walls of concrete involve setting up a pair of spaced, rigid flat surfaces, generally formed from plywood, in an upstanding configuration. Fluent concrete material is then poured into the gap to create an upstanding wall when the concrete seats. Generally, such walls are formed atop an existing footing.

[0004] Existing wall forming methods suffer from several drawbacks:

[0005] 1. The use of removable rigid surfaces requires their installation at the location of the proposed foundation wall. Once the concrete is set in place, the bracing members must be removed (or broken) to enable the rigid surfaces to be stripped from the formed wall and taken to the next jobsite. This requires additional labour. In addition, there can be damage to the rigid surfaces both from the acidity of the concrete as well as mishandling during shipment, installation and stripping.

[0006] 2. Most foundation walls are required by code to provide a certain level of insulation. With the use of rigid removable wall forms, the insulation (normally a rigid insulation) must be installed after the formwork has been removed.

[0007] 3. The outside surface of most concrete foundation walls are required by code to he damp proofed to prevent moisture from surrounding soils from penetrating the concrete. Using existing wall forming techniques, this must be done after the rigid surfaces has been stripped from the concrete. This adds additional expense and labour to the process of creating a foundation wall.

[0008] To overcome the problems with removable rigid form assemblies, alternative techniques and equipment have been developed. For example, U.S. Pat. No. 4,154,061 to Umemoto discloses a fabric form for concrete formed from reinforced fabric sheets. The resulting fabric forms are suitable for low footings, but the forms are insufficiently rigid to permit formation of rigid, vertically upstanding foundation walls. Concrete when constrained in vertical fabric forms tends to flow under gravity to cause outward bulging of the fabric walls with an vertically extending S curve such that the fabric form fails to maintain the desired straight vertical wall shape.

[0009] Co-inventor, Richard N. Fearn, of the present invention is the owner of U.S. Pat. Nos. 5,224,321 and 5,794,393, the disclosures of which are incorporated herein by reference. These patents disclose the notion of using fabric to create concrete forms using an external framework or an internal bracing system to reduce bulging of the fabric side walls. Patent Co-operation Treaty International application No PCT/CA98/00619 owned by inventor Fearn discloses a fabric form system designed for the efficient and inexpensive production of footings using an external support structure for the fabric.

SUMMARY OF THE INVENTION

[0010] In view of the above discussion, there is a need for a fabric form system to create walls, particularly foundation walls, formed from concrete. To address this need, the inventors have developed an system that relies on a rigid form surface in combination with a flexible, fabric surface. The rigid surface and the flexible fabric surfaces are interconnected by an array of links that serve to prevent bulging of the fabric surface when fluent concrete material is introduced between the rigid surface and the fabric surface. The rigid surface acts to maintain the form assembly in the desired generally vertical orientation.

[0011] Accordingly, the present invention provides a wall form assembly comprising:

[0012] a substantially rigid surface to maintain the form assembly in a pre-determined orientation;

[0013] at least one flexible, fabric surface spaced from the rigid surface to define a container with side walls; and plurality of flexible links extending between the side walls of the container to position the at least one flexible, fabric surface with respect to the rigid surface.

[0014] In a further aspect, the present invention provides a method for constructing a wall comprising the steps of:

[0015] connecting together a substantially rigid surface and at least one spaced flexible, fabric surface by a plurality of flexible links to define a container with side walls, the rigid surface acting to maintain the flexible, fabric surface in a desired configuration; and

[0016] supplying a flowable and settable wall material to substantially fill the container to form a wall when the wall material has set.

[0017] In a still further aspect the present invention provides a wall form assembly comprising:

[0018] a structural surface to maintain the form assembly in a pre-determined orientation;

[0019] at least one flexible membrane interconnected with the structural surface by a plurality of flexible links to position the at least one flexible membrane with respect to the structural surface to define a space therebetween to receive a flowable and settable material.

[0020] The wall form assembly and method of the present invention offer the advantage of significant weight reduction by replacing a rigid surface with a fabric surface. In some cases the rigid surface is a light weight insulation panel which offers additional weight savings. The result is a wall form assembly that is easier to ship, carry and install. There is less labour involved as in most embodiments, the rigid and fabric surfaces are left in place on the formed wall so that stripping is not required. In addition, the rigid surface is preferably a rigid insulation panel and the. fabric surface is preferably treated to be water impermeable so subsequent insulation and water proofing of the formed wall are unnecessary.

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Aspects of the present invention are illustrated, merely by way of example, in the accompanying drawings in which:

[0022]FIG. 1 is a perspective view of a prior art wall form system using steel supports, plywood and steel ties;

[0023]FIG. 2 is a section view through a completed foundation wall and the wall form assembly according to an embodiment of the present invention, and is as seen on line 2-2 of FIG. 2a;

[0024]FIG. 2a is a fragmentary side elevation view of a portion of the completed foundation wall formed using the wall form assembly of the present invention;

[0025]FIG. 3 is a detail view of the flexible fabric layer of woven material according to a preferred embodiment showing links extending from the woven material;

[0026]FIG. 4 is a detail view of an embodiment of the present invention that uses a rigid insulation panel as the rigid surface;

[0027]FIG. 5 is a detail view showing a preferred manner in which the links are received in cavities in the rigid insulation panel;

[0028]FIG. 6 is a detail view similar to FIG. 5 showing the links glued in place within the cavities;

[0029]FIG. 7 is a detail view of an alternative embodiment in which the links extending from the flexible fabric surface are mounted to the rigid surface by hooks;

[0030]FIG. 8 is a detail view of a further embodiment formed from an outer flexible, fabric layer, a intermediate rigid insulation layer and an outer rigid layer with links extending between the outer layers through the intermediate layer;

[0031]FIG. 9 is a detail view of a still further embodiment formed from a pair of outer flexible fabric layers sandwiching a rigid intermediate layer spaced equidistantly from the fabric layers;

[0032]FIG. 9a is a detail view of an alternative embodiment similar to that of FIG. 9 except that the rigid intermediate layer is adjacent one of the fabric layers;

[0033]FIG. 10 is a detail view showing a preferred corner bracing arrangement; and

[0034]FIG. 11 is a detail view of a clip used with the wall form assembly of the present invention to hold reinforcing bar.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] Referring to FIG. 1, there is shown a conventional prior art wall form structure 10 positioned atop an existing footing 12. The wall form structure includes a series of plywood or steel panels 14 that are supported by an external framework 16 to define a pair of spaced, rigid planar surfaces with a cavity 18 therebetween to received fluent concrete. The spacing of the panels 14 is maintained by rigid steel or plastic rods 20 that extend between the panels. Once the concrete is set, external framework 16 and panels 14 are removed in a process known as “stripping” to leave a completed tree standing wall atop footing 12.

[0036] The wall form assembly of the present invention was developed to minimize or avoid the requirement of stripping the completed wall. FIGS. 2 and 2a. show an exemplary wall form assembly 30 according to the present invention in cross-section and elevation. The wall form assembly is created atop an existing footing 12 that sits on site surface 15. The wall form assembly preferably comprises a structural surface 32 to maintain the form assembly in a pre-determined orientation and at least one flexible membrane 34 interconnected with the structural surface 32 by a plurality of flexible links 36. Links 36 act to position flexible membrane 34 with respect to the structural surface 32 to define a space 38 therebetween to receive a flowable and settable material such as concrete 40.

[0037] Preferably, structural surface 32 comprises a substantially rigid surface such as series of joined panels of plywood that are braced using conventional upper and lower supports 42 and 43, respectively, to maintain the structural surface in an upright, generally vertical orientation. It will be readily apparent to a person skilled in the art that alternative bracing arrangements for supporting structural surface 32 are possible.

[0038] Structural surface 32 must be sufficiently rigid and of appropriate strength to support the pressure of the concrete while setting and the tensile loads generated by links 36 as flexible membrane 34 acts to confine the concrete at the opposite side of the form assembly from structural surface 32. To this end, structural or rigid surface 32 can be formed from panels of plywood as previously mentioned. Alternatively, surface 32 can be formed from panels of rigid insulation material. This technique has the advantage that walls are pre-formed with insulation and a separate application of insulation of wall formation is unnecessary. By way of example, the rigid insulation material can be conventional extruded polystyrene (XPS) or expanded polystyrene (EPS) panels.

[0039] Flexible membrane 34 is selected to be of sufficient strength to resist the pressure of the fluent concrete without tearing. Preferably, flexible membrane 34 comprises a woven fabric surface. An example of an appropriate woven material is manufactured by Fabrene, Inc under the name FABRENE. Another example is a woven polypropylene geotextile fabric material as manufactured and distributed by AMOCO Corporation of Mich., U.S. However, any non-woven flexible material member such as polymer sheeting can be substituted for the woven fabric material.

[0040] Flexible membrane 34 can be semi-rigid. For example, flexible membrane 34 can be formed from wire mesh with a covering membrane. Alternatively, flexible membrane 34 can be a plastic sheet. It is sufficient that flexible membrane 34 be a relatively light weight material that is capable of withstanding the tensile forces generated by the flowable concrete.

[0041] As best shown in FIG. 2a, flexible membrane 34 is preferably supplied in the form of discrete sheets in which each sheet is joined to an adjacent sheet by a fastener. In FIG. 2a, the sheets are formed from woven fabric material that are joined by zippers 45. Alternative fasteners include but are not limited to hook and loop fasteners, double sided tape and staples applied into a board overlapping the edges of the sheets. The fasteners used will tend to depend upon the material of flexible membrane 34.

[0042] Structural surface 32 and flexible membrane 34 are preferably supplied in sheets or panels of uniform dimensions to allow form walls of a desired length to be assembled. For example, panels dimensioned to be 4 feet wide by 8 feet high provide components parts that are conveniently handled for efficient assembly. Rigid structural surfaces 32 can be joined together in a standard manner such as nailing, gluing or interlocking of tongue and groove connectors 98 formed in the side edges (see FIG. 10).

[0043] Referring to FIG. 2, it is necessary to brace flexible membrane 34 to minimize bulging of the membrane and ensure sealing of the upper and lower edges. Preferably, this is achieved by constructing a framework adjacent the flexible membrane comprising a lower kicker 37 and an upper whaler 39 to which the flexible membrane is stapled at 47. A series of spaced vertical braces 41 extend between the kicker and whaler. Preferably, the kicker, whaler and braces are formed from 2×4 lumber count to size.

[0044] Flexible membrane 34 is preferably impermeable to water to provide waterproofing for the finished wall. In the event that flexible membrane 34 is a woven fabric surface a waterproof coating 48 can be applied to prevent water access. In addition, a water drainage layer 49 is provided adjacent the waterproof coating to move water away from the constructed wall.

[0045] As best shown in FIG. 2, flexible membrane 34 and rigid structural surface 32 define a container with side walls to confine concrete in a flowable state. Membrane 34 and rigid surface 32 are joined together by a plurality of flexible links 36 extending between the side walls of the container that serve to position the flexible membrane with respect to the anchored rigid structural surface. To spread the tensile forces generated by the flowable concrete as evenly as possible it is preferably that flexible links 36 extend between the side walls of the container in a regular pattern on about 3 inch centers (see FIG. 2a). The length of the links will vary depending on the thickness of the concrete wall being poured. For example, flexible lines 36 that are 8 inches long are used form a wall that is of average thickness.

[0046] Flexible links 36 must be securely anchored to the surfaces between which the links extend. In the case of a flexible membrane 34 formed from a woven fabric material, it is preferable that each link 36 comprises a tie 48 woven or sewn into the material. As best shown in FIG. 3, which is a detail view of a woven fabric surface 50, each tie 48 comprises a drop stitch defining a loop of material extending from the warp or weft of surface 50. At the opposite end of each tie 48 from woven fabric surface 50, the tie is preferably anchored to structural surface 32. By way of example, FIGS. 4 to 6, show various techniques by which ties 48 are connected to a rigid insulation panel 54. In FIG. 4, holes 56 are formed through the insulation panel aligned with ties 48. The ties are inserted through holes 56 such that their distal ends 58 protrude from the opposite side of the insulation panel. The ties are glued in place using an appropriate polymer glue. In FIGS. 5 and 6, cavities 60 are formed in the rigid insulation to receive the distal ends of the ties. Cavities 60 are filled with polymer glue 62 to anchor the tie ends to the rigid insulation.

[0047]FIG. 7 illustrates a still further anchoring technique for connecting ties 48 to the structural surface 32. In this case, structural surface 32 can be a plywood panel or a rigid insulation panel. Hook members 64 are mounted to the structural surface 32 by gluing, nailing, stapling or the like. Hook members 64 are preferably injection molded plastic pieces. Each hook members 64 is inserted through the loop of a tie 48 to interconnect flexible woven surface 5O with rigid structural surface 32. It will be appreciated by a person skilled in the art that alternative techniques are possible for anchoring flexible links 36 to flexible membrane 34 and rigid structural surface 32. It is sufficient that flexible links 36 be securely anchored at each surface in order to be able to resist tensile force resulting from introduction of the flowable concrete between the surfaces.

[0048] Ties used with a woven fabric flexible surface will preferably be formed from the same fabric material as the woven surface. It is also possible to make the ties from flexible plastic that is bonded at each end to one of structural surface 32 and flexible membrane 34.

[0049] If the rigid structural surface 32 is formed from plywood, the wall form system illustrated in FIG. 7 is similar to a conventional form as illustrated in FIG. 1 except for the significant modification that one rigid surface is replaced with a flexible membrane joined to the remaining rigid surface by an array of flexible links. One advantage of such an arrangement is that the wall form of the present invention is significantly lighter in weight and is therefore easier to manipulate and install. Material costs are also reduced. There is less labour involved as only the plywood surface needs to be stripped once the concrete is set. The flexible membrane remains in place against one side of the finished wall to act as a damp proofing barrier.

[0050] If the rigid structural surface 32 is formed from a rigid insulation panel, the wall form system illustrated in FIG. 7 offers the additional advantage that the rigid insulation panel performs a dual function as a side wall co-operating with the flexible membrane to contain the flowable and an insulating member. Once the concrete is set, no stripping is required as the rigid insulation panel on one side and the flexible member on the opposite side of the wall remain in place. The rigid insulation panel and flexible membrane combination provide a light weight modular wall form assembly that enjoys reduced shipping, installation and handling costs.

[0051] The wall form assembly of the present invention can be set up in alternative arrangements from that illustrated in FIG. 7

[0052] For example, FIG. 8 shows an arrangement in which a rigid structural surface 32 (a plywood panel or a rigid insulation panel) defines one side wall of the form. An intermediate rigid surface 70 preferably formed from a rigid insulation panel defines a middle layer, and an outer flexible membrane 34 ( a woven fabric surface) defines the other side wall of the form. In the wall form assembly of FIG. 8, flexible links 36 extend between the outer rigid structural surface 32 and the outer flexible membrane 34 through openings 72 formed in the intermediate rigid surface 70.

[0053]FIG. 9 illustrates a further embodiment of the wall form assembly of the present invention in which a first outer flexible membrane 75 (a woven fabric surface) defines one side wall of the form. There is an intermediate rigid surface 78 comprising a rigid insulation panel that defines a middle layer and a second outer flexible membrane 80 that defines the other side wall of the container. Flexible links in the form of loop ties 82 extend between the first and second outer flexible membranes through openings formed in the intermediate insulation panel. This wall form assembly provides a light weight structure in which the middle insulation layer is braced to support the entire form. Once the concrete sets, the internal middle insulation layer is protected from the environment by a layer of concrete and the outermost flexible membranes which remain in place.

[0054] As illustrated in FIG. 9, the middle insulation panel 78 can be positioned essentially equidistantly from the first and second outer flexible membranes 75 and 80. In this configuration, when concrete is poured, the insulation is sandwiched between two thicknesses of concrete.

[0055] Alternatively, as illustrated in FIG. 9a, the intermediate insulation panel 78 can be positioned to contact one of the first and second outer flexible fabric surfaces to create a single internal concrete layer sandwiched between a woven fabric layer 75 on one side and an insulation panel 78 and a woven fabric layer 80 on the opposite side. This arrangement is preferred as it provides a single concrete wall that is protected from the environment. The use of two outer flexible membranes provides the best possible anchoring for the ends of links 82.

[0056]FIG. 10 shows a preferred tensioning arrangement installable at changes in direction of the wall form assembly to ensure that corners are properly shaped. FIG. 10 is a perspective view of a corner in a wall form 30 constructed according to the present invention with a rigid structural surface 32 and a flexible membrane 34 defining the outer form walls joined by a plurality of flexible links 36. Within the interior 38 of the form between the outer form walls, a corner tensioning member 85 is provided. Tensioning member 85 is positionable adjacent a corner region 89 and is mounted to rigid structural surface 32 via a mounting bracket in the form of angle bracket 88. The angular separation of the surfaces of angle bracket 88 is selected to corresponding to the angle of the corner region. Tensioning member 85 includes a protruding angled flange 90 that extends across interior 38 from rigid structural surface 32 for attachment to flexible membrane 34 to support and tension the membrane through the change in direction. The flexible membrane is stapled or glued along edge 92 of flange 90 which defines the corner edge of the form assembly. Protruding flange 90 is formed with a plurality of openings 95 therethrough to allow for the free passage of flowable concrete around the corner.

[0057]FIG. 11 is a top plan view illustrating a clip 100 mountable between panels of rigid insulation 32 to hold vertically aligned reinforcing bar 102 in place within interior 38 of the wall form. Clip 100 is preferably formed from molded plastic.

[0058] Although the present invention has been described in some detail by way of example for purposes of clarity and understanding, it will be apparent that certain changes and modifications may be practiced within the scope of the appended claims. 

We claim;
 1. A wall form assembly comprising: a substantially rigid surface to maintain the form assembly in a pre-determined orientation; at least one flexible, fabric surface spaced from the rigid surface to define a container with side walls; and a plurality of flexible links extending between the side walls of the container to position the at least one flexible, fabric surface with respect to the rigid surface.
 2. A wall form assembly as claimed in claim 1 in which the at least one flexible, fabric surface is a woven material and each of the flexible links comprises a tie extending from the material.
 3. A wall form assembly as claimed in claim 2 in which each tie comprises a loop of material.
 4. A wall form assembly as claimed in claim 2 in which each tie comprises a drop stitch of the warp or weft of the woven material.
 5. A wall form assembly as claimed in claim 3 in which each loop is anchored to the substantially rigid surface.
 6. A wall form assembly as claimed in claim 5 in which each loop is anchored to the substantially rigid surface by a hook member mounted to said surface.
 7. A wall form assembly as claimed in claim 5 in which each loop is anchored to the substantially rigid surface by gluing to said surface.
 8. A wall form assembly as claimed in claim 1 in which the substantially rigid surface is formed from panels of plywood.
 9. A,wall form assembly as claimed in claim 1 in which the substantially rigid surface is formed from panels of rigid insulation material.
 10. A wall form assembly as claimed in claim 9 in which the rigid insulation material is extruded polystyrene (XPS).
 11. A wall form assembly as claimed in claim 9 in which the rigid insulation material is expanded polystyrene (EPS).
 12. A wall form assembly as claimed in claim 1 in which the at least one flexible, fabric surface is formed from a plurality of fabric sheets with each sheet being joined to an adjacent sheet by a fastener.
 13. A wall form assembly as claimed in claim 12 in which the fastener comprises a zipper.
 14. A wall form assembly as claimed in claim 1 in which the at least one flexible, fabric surface is impermeable to water.
 15. A wall form assembly as claimed in claim 14 in which the flexible, fabric surface is rendered impermeable to water by a waterproof coating.
 16. A wall form assembly as claimed in claim 15 including a water drainage layer adjacent the waterproof coating.
 17. A wall form assembly as claimed in claim 1 in which the plurality of flexible links extend between the side walls of the container in a regular pattern on about 3 inch centers.
 18. A wall form assembly as claimed in claim 1 in which the substantially rigid surface defines one side wall of the container and a single flexible fabric surface defines the other side wall of the container.
 19. A wall form assembly as claimed in claim 1 in which an outer substantially rigid surface defines one side wall of the container, an intermediate rigid surface defines a middle layer, and an outer flexible fabric surface defines the other side wall of the container.
 20. A wall form assembly as claimed in claim 19 in which the intermediate rigid surface is a rigid insulation panel.
 21. A wall form assembly as claimed in claim 19 in which the flexible links extend between the outer substantially rigid surface and the outer flexible fabric surface through openings formed in the intermediate rigid surface.
 22. A wall form assembly as claimed in claim 1 in which a first outer flexible fabric surface defines one side wall of the container, an intermediate rigid surface defines a middle layer and a second outer flexible fabric surface defines the other side wall of the container.
 23. A wall form assembly as claimed in claim 22 in which the intermediate rigid surface is a rigid insulation panel.
 24. A wall form assembly as claimed in claim 22 in which the flexible links extend between the first and second outer flexible fabric surfaces through openings formed in the intermediate rigid surface.
 25. A wall form assembly as claimed in claim 23 in which the intermediate rigid surface is spaced substantially equidistantly from the first and second outer flexible fabric surfaces.
 26. A wall form assembly as claimed in claim 23 in which the intermediate rigid surface is positioned to contact one of the first and second outer flexible fabric surfaces.
 27. A wall form assembly as claimed in claim 1 including a corner tensioning member installable at changes in direction of the wall form assembly.
 28. A wall form assembly as claimed in claim 27 in which the corner tensioning member comprises a mounting bracket positionable against the rigid surface between the side walls of the container adjacent a corner region, the mounting bracket including a protruding flange that extends into the corner region for attachment to the flexible fabric surface to support and maintain tension of the fabric surface through the change in direction in the wall form assembly.
 29. A wall form assembly as claimed in claim 28 in which protruding flange is formed with a plurality of openings therethrough.
 30. A wall form assembly comprising: a substantially rigid surface to maintain the form assembly in a pre-determined orientation; at least one flexible, fabric surface spaced from the rigid surface to define a cavity therebetween; and a plurality of flexible links extending between the flexible, fabric surface and the substantially rigid surface to position the fabric surface with respect to the rigid surface.
 31. A method for constructing a wall comprising the steps of: connecting together a substantially rigid surface and at least one spaced flexible, fabric surface by a plurality of flexible links to define a container with side walls, the rigid surface acting to maintain the flexible, fabric surface in a desired configuration; and supplying a flowable and settable wall material to substantially fill the container to form a wall when the wall material has set.
 32. The method of claim 31 in which the substantially rigid surface is positioned to define one side wall of the container and a single flexible fabric surface is positioned to define the other side wall of the container.
 33. The method of claim 31 in which an outer substantially rigid surface is positioned to define one side wall of the container, an intermediate rigid surface is positioned to define a middle layer, and an outer flexible fabric surface is positioned to define the other side wall of the container.
 34. The method of claim 33 in which the intermediate rigid surface is a rigid insulation panel.
 35. The method of claim 33 in which the flexible links extend between the outer substantially rigid surface and the outer flexible fabric surface through openings formed in the intermediate rigid surface.
 36. The method of claim 31 in which a first outer flexible fabric surface is positioned to define one side wall of the container, an intermediate rigid surface is positioned to define a middle layer and a second outer flexible fabric surface is positioned to define the other side wall of the container.
 37. The method of claim 36 in which the intermediate rigid surface is a rigid insulation panel.
 38. The method of claim 36 in which the flexible links extend between the first and second outer flexible fabric surfaces through openings formed in the intermediate rigid surface.
 39. The method of claim 31 including the additional step of installing a corner tensioning member at changes in direction of the wall form assembly.
 40. The method of claim 39 in which the corner tensioning member is a mounting bracket positionable against the rigid surface between the side walls of the container adjacent a corner region, the mounting bracket including a protruding flange that extends into the corner region for attachment to the flexible fabric surface to support and maintain tension of the fabric surface through the change in direction in the wall form assembly.
 41. A wall form assembly comprising: a structural surface to maintain the form assembly in a pre-determined orientation; at least one flexible membrane interconnected with the structural surface by a plurality of flexible links to position the at least one flexible membrane with respect to the structural surface to define a space therebetween to receive a flowable and settable material.
 42. A wall form assembly as claimed in claim 41 in which the structural surface is a rigid surface.
 43. A wall form assembly as claimed in claim 42 in which the rigid surface is formed from panels of rigid insulation.
 44. A wall form assembly as claimed in claim 41 in which the at least one flexible membrane is a flexible material able to resist tensile forces.
 45. A wall form assembly as claimed in claim 41 in which the at least one flexible membrane is a woven fabric material and each of the flexible links comprises a tie woven into the material. 